Cayley expects, in the usual case, to be run with a configuration file, though it can also be run purely through configuration flags. The configuration file contains a JSON object with any of the documented parameters.
Cayley looks in the following locations for the configuration file
All command line flags take precedence over the configuration file.
Determines the type of the underlying database. Options include:
mem: An in-memory store, based on an initial N-Quads file. Loses all changes when the process exits.
leveldb: A persistent on-disk store backed by LevelDB.
mongodb: Stores the graph data and indices in a MongoDB instance. Slower, as it incurs network traffic, but multiple Cayley instances can disappear and reconnect at will, across a potentially horizontally-scaled store.
Where does the database actually live? Dependent on the type of database. For each datastore:
mem: Path to a triple file to automatically load
leveldb: Directory to hold the LevelDB database files
mongodb: “hostname:port” of the desired MongoDB server.
The hostname or IP address for Cayley’s HTTP server to listen on. Defaults to all interfaces.
The port for Cayley’s HTTP server to listen on.
If true, disables the ability to write to the database using the HTTP API (will return a 400 for any write request). Useful for testing or instances that shouldn’t change.
The number of triples to buffer from a loaded file before writing a block of triples to the database. Larger numbers are good for larger loads.
See Per-Database Options, below.
db_options object in the main configuration file contains any of these following options that change the behavior of the datastore.
No special options.
The size in MiB of the LevelDB write cache. Increasing this number allows for more/faster writes before syncing to disk. Default is 20, for large loads, a recommended value is 200+.
The size in MiB of the LevelDB block cache. Increasing this number uses more memory to maintain a bigger cache of triple blocks for better performance.
The name of the database within MongoDB to connect to. Manages its own collections and indicies therein.